Slip



Patented Aug. 27, 1935 A'NT OFFICE SLIP Erwin Burns, Los Angeles, and Harry P. Wickersham, Huntington Park, Calif.

Application January 7, 1935, Serial No. 664

11 Claims.

This invention relates to pipe handling devices and has particular reference to slips for use in the rotary table of a well drilling rig. A general object of the invention is to provide simple, practical slips having novel and effective means for gripping pipe and like objects.

Another object of the invention is to provide slips for use in a rotary table embodying a plur-ality of super-imposed cams or gripping dogs that automatically cam or move into tight gripping and holding engagement with the pipe when the slips assume the weight of the pipe.

Another object of the invention is to provide slips of the character mentioned in which the dogs or cams: are simple members that may be easily removed for replacement, etc.

Another object of the invention is to provide slips of the character mentioned in'which the slip bodies which carry the pipe gripping dogs or cams are simple and inexpensive of manufacture. The pipe gripping members or cams of the present invention have substantially disc shaped major portions whereby they may becarried in partially cylindrical openings in the inner face of the slip body which openings may be easily and inexpensively drilled or provided in the body.

A further object of the invention is to provide slips of the character mentioned that are positive and dependable in operation and that may be easily manipulated.

Other objects and features 'of the invention will be more fully and better understood from the following detailed description of a typical preierred form and application of the invention,

` throughout which description reference is made to the accompanying drawing, in which:

. Fig. l is a top plan view of a setoi slips embodying the invention arranged in the spider or bush-` ing of a rotary table or the like. Fig.r 2 is an enlarged vertical detailed sectional View of one of the slips, and Figs. 3 and 4 are transverse detailed sectionalviews taken substantially as indicated by lines 3--3 and -4, respectively, on Fig. 2.

The present invention may be embodied in slips varying somewhat in character and in slips for use in rotary tables and rotary table spiders and bushings of different types. In the drawing we have illustrated the invention embodied in a set of three slips S designed `for arrangement in the tapered opening O of a spider or bushing B of the type employed in the rotary table of a well drilling rig. It is to be understood that the invention may be embodied in other forms and in sets of two, four, or more slips. As the several slips S are identical, `we will proceed with a de- (Cl. .Z4-263) tailed description of one slip, it being understood that suoh description may apply equally well to the other slips S of the set.

` The slip S provided by this invention includes, generally, a body i0 for arrangement in the opening O, and means Il carried by the body I0 for gripping a pipe P. Y

The body it may be varied considerably in shape and construction without departing from the broaderaspects of the invention. The par 10 ticular b'ody il) illustrated in the drawing is an integral hollow member having'a Ylongitudinal opening or cavity I2. The slip body l0 is shaped to nt or operate in the opening O having its major external surface I3 convex and tapered downwardly and inwardly to cooperate with the wall of` the opening. The upper and lower ends of the body IB may be iiat and horizontal and the op`` posite sides` I4 of the body may be flat and substantially parallel. Radial corner faces I5 extend from the sides i4 to the inner face or surface IS of the body. The radial faces I5 are adapted to cooperate with the corresponding faces I5 of adjacent slips S. The inner surface I6 of the body i0 is substantially vertical and is concave being cylindrically concaved concentric to the longitudinal aXisof the opening O. A suitable handle H is pivoted to the body I0 at Il, to :facilitate the easy handling and carrying of the slip.

The means II for engaging and gripping the pipe P is an important feature of the invention and is in the nature of a cam means comprising super-imposed cams or dogs I8 carried by the body i0 to cooperate with the pipe P. If desired, a single series of cams or dogs I8 may be provided on the slip body II). However, it is preferred to provide a plurality 'of circumferentially spaced series of dogs I8 on each slip body Il). 'Ihe cams or dogs I8 are arranged in vertical or longitudinal openings I 9 in the inner side or face IS of the body IFJ. In the particular form of the invention shown in the drawing there are three substantially equally spaced openings I9 for holding three series of dogs or cams I 8. 'I'he dogs or cams I8 are preferably alike or identical in shape and size. In accordance with the inven tion the bodies or major portions of the dogs IB are partially disc shaped in plan elevation and have peripheries 26 which extend for more than 180. The openings I9 are shaped to hold the major portions of the dogs I3, being in the nature of round or cylindrical bores which have sides open at the inner surface l'o of the body ID. The cylindrical walls of the openings I9 are each of 23 for biting into the pipe.

directly supported one upon the other.

551" ings I9 to retain the dogs in the openings.

more than 180 in circumferential extent and the dogs I8 are proportioned so that their maj or portions are prevented from passing horizontally out of the openings I9. Lugs or tongues 2I are pro- 5 vided on the dogs to grip the pipe P and extend through the open forward sides of the openings I9 to project from the inner surface I6 of the body IIJ. The active inwardly facing ends 22 of the tongues 2I are preferably cylindrically con- 10 caved to substantially conform to the periphery 25 when the engagement of the tongues 2| with the pipe P causes the tongues to move downwardly. The series of dogs I8 are normally inclined upwardly andinwardly with respect to the longitudinal axis of the pipe P. The peripheral edges or peripheries 24 of the major portions of the dogs are bevelled or rounded to permit the free tilting or pivoting of the dogs. The series of dogs I8 are preferably supported in the openings I 9 in a manner which allows them to readily rock or pivot. The openings I9 terminate at their lower ends at shoulders 25. Reduced openings 26 extend upwardly from the lower end of the body I0 to the shoulders 25. Pins Z'I are inserted in the reduced openings 26 from their upper ends 40. and have heads 28 bearing on the shoulders 25.

The upper surfaces of the heads 28 are curved upwardly and inwardly or in the same direction as the upper and lower surfaces 28 of the dogs so that the lower sides 28 of the lowermost dogs 45.' may evenly rest on the heads 28 when the dogs are in their normal positions. The pins 2'I may be easily replaced or repaired if they become Worn. Y

Means is provided for retaining the series of 50i dogs I8 in the openings I9 and for limiting the extent of tilting or pivoting of the dogs. A retaining plate 38 is removably attached to the upper end of the body II) by bolts or screws 3! and extends across the upper ends of the several open- The retaining plate 30 may be counter-sunk in the upper end of the body Il). The series of dogs I8 are proportioned so that the upper sides 28 of the uppermost dogs are adapted to cooperate 60.: with the plate 30 to limit tilting or pivoting of the dogs. It is preferred to relate the parts so that the dogs I8 are prevented from pivoting to or beyond horizontal positions.

In employing the slips S of the invention the 65v bodies I0 are arranged in the opening O so that their outer surfaces I 3 may cooperate with the wall of the opening and so that the active ends 22 of the tongues 2I may engage the pipe P. When the weight of the pipe P is allowed to set- 70: tle on the set of slips the tongues 2I engaging the pipe are caused to move downwardly. 'I'his downward movement of the tongues 2| of the several series of dogs I8 is accompanied by upward swinging or pivoting of the major portions '5 of. the dogs. The dogs I8 in having transversely curved upper and lower surfaces 2U may freely tilt or pivot in this manner. The pivoting of the dogs I8 cams or moves the active ends 22 of the tongues 2| into tight gripping cooperation with the pipe P. In practice the edges 23 of the tongues may bite into the pipe to dependably support the same. It is to be understood that the multiplicity of dogs I8 in each series is free to simultaneously pivot and cam into tight holding engagement with the pipe. S is provided with a plurality of series of dogs I8 the pipe P is gripped at a multiplicity of circumferentially spaced points by the rows of superimposed dogs. The dogs I8 are effective in dependably gripping and holding the pipe P. When the pipe P is raised or moved upwardly the tongues 2I which are in active engagement with the pipe are also caused to move upwardly. This upward movement of the tongues 2l is accompanied by downward and inward pivoting of the dogs so that the dogs are automatically returned to their normal retracted positions when the pipe is moved upwardly. The automatic retraction of the dogs I8 frees the slips from the pipe allowing the slips to be readily removed from the rotary table opening O. The dogs I8 may be easily removed from the openings I9 by detaching the plates 38. The body I8 and the dogs I8 are simple and inexpen sive of manufacture. Dogs I8 having tongues 2| of different lengths may be arranged in the openings I9 to adapt the slips for properly handling pipe of different diameters.

I-l'aving described only a typical form and application of our invention, we do not wish to be limited or restricted to the specific form and application herein set forth, but wish to reserve to ourselves any medications or variations that may appear to those skilled in the art or fall within the scope of the following claims:

Having described our invention, we claim:

l. A slip for use in a rotary table including a body having an opening open at its inner side, and super-imposed dogs in the opening projecting from said inner side to contact a pipe, the dogs being transversely bowed to have curved slidably contacting surfaces.

2. A slip for use in a rotary table including a body having an opening open at its inner side, super-imposed dogs in the opening having curved contacting upper and lower surfaces, and tongues on the dogs projecting through the open side of the opening to contact a pipe.

3. A slip for use in a rotarytable including a body having an opening open at its inner side, super-imposed cams in the opening curved in cross section to have curved cooperating upper Where each slip and lower surfaces, tongues on the cams projecting through the open side of the opening to engage a. pipe, and means supporting the cams for pivotal movement.

4. A slip for use in a rotary table including a body having an opening open at its inner side, super-imposed cams in the opening curved in cross section to have curved slidably cooperating upper and lower surfaces, tongues on the cams projecting through the open side of the opening to engage a pipe, and means supporting the cams in inclined positions where their tongues project upwardly and inwardly.

5. A slip for use in a rotary table including a body having an opening open at its inner side, super-imposed pivotable dogs in the opening curved in cross section to have curved slidably contacting upper and lower sides, tongues on the dogs projecting through the open side of the opening to engage a pipe, means for normally supporting the dogs in inclined positions, and means for limiting pivotal movement of the dogs.

6. A slip for use in a rotary table including a body having a partially cylindrical opening open at its inner surface, and a plurality of substantially disc shaped super-imposed dogs in the opening having tongues projecting through the open side of the opening to engage a pipe.

'7. A slip for use in a rotary table including a body having a partially cylindrical opening open at its inner surface, and a plurality of substantially disc shaped super-imposed dogs in the opening having curved contacting upper and lower surfaces, the dogs including tongues projecting through the open side of the opening to engage a pipe.

8. A slip for use in a rotary table including a body having spaced substantially vertical partially cylindrical openings open at its inner side, and multiplicities of super-imposed dogs in the openings having tongues projecting through the open sides of the openings to engage a pipe.

9. A slip for use in a rotary table including a body having an opening open at its inner side, super-imposed cams in the opening having curved cooperating upper and lower surfaces, tongues on the cams projecting through the open side of the opening to engage a pipe, and means supporting the cams for pivotal movement, said means including a curved inclined seat at the lower end of the openings.

10. A slip for use in a rotary table including a body having an opening open at its inner side, super-imposed dogs in the opening of curved cross section to have curved slidably contacting surfaces, and tongues on the dogs projecting through the open side of the opening to contact a pipe, the ends of the dogs being curved to substantially conform to the pipe and having edges for gripping the pipe.

l1. A slip of the character described including v-a body having an opening open at its inner side, a multiplicity of superimposed cams in the opening having their upper and lower surfaces curved downwardly and outwardly relative to said side of the body, and tongues on the cams projecting through the open side of the opening to engage a pipe, the said surfaces sliclably cooperating to allow free relative movement between the cams during actuation and retraction of the cams.

ERWIN BURNS. HARRY P. WICKERSHAM. 

